Opening the Blinds- activity analysis of movement

 

Every morning, I like to start my day by opening the blinds and letting the natural sunlight in. In order to do this action, I have to flex my shoulder, slightly adduct my wrist, and flex my fingers to grasp the pull string. Once I have a firm grasp on the pull string, I simultaneously extend my shoulder and flex my elbow to pull the blinds up. Once the binds are at the length I prefer, I let the pull string go by extending my fingers, slightly abducting my wrist, and I return my shoulder and elbow joints to the neutral position that I was in before I started.  The flexion of the shoulder and elbow joints are occurring in the sagittal plane about the frontal axis. At the elbow joint, the osteokinematics is extension to flexion, and it is an open kinematic chain. For arthrokinematics at the humeroulnar joint, the trochlear notch of the ulna is concave, rolling anteriorly and sliding anteriorly and distally on the distal humerus which is convex. As for the humeroradial joint, the head of the radius is concave, and it will be rolling and sliding anteriorly on the distal, lateral humerus which is convex. The prime mover for elbow flexion is the biceps brachii, which performs a concentric contraction when opening the blinds.